with Variable Stroke. 745 corresponding adjustment of stroke. The result is roughly the same, for pressure x stroke = work done. The cam F is peculiar in shape; it is shewn under full load, having turned through three-quarters of a revolution, in a right- hand direction. Its highest point is'at-f-, and its lowest at #, and when the load is removed, the cam turns leftward until the projection at * stops itself against the projection G. Similarly the earn shewn dotted serves when the engine rotation is reversed, the projection j being then acted upon. Both G and j are one with the shoe-plate M, but lie in different planes, so that the two cams, also in one piece, may rotate without interference.